Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Microwave anomaly of Maduo MS7.4 earthquake derived by improved two-step difference method
Liu Shanjun, Ji Meiyi, Song Limei, Wei Lianhuan
 doi: 10.11939/jass.20210193
[Abstract](2) [FullText HTML](0) [PDF 3237KB](0)
In response to the shortcomings of the two-step difference method for extracting seismic microwave anomalies proposed in 2011, an improved two-step difference method which incorporates hierarchical clustering and wavelet analysis is proposed to overcome the problems resulted from ignoring the brightness temperature differences caused by ground cover types and the lack of robustness of the brightness temperature background field in the original method, thus making the anomaly results more reasonable in terms of spatial pattern and anomaly amplitude. The method is applied to the microwave anomaly extraction of the MS7.4 earthquake in Maduo County, Qinghai Province on May 22, 2021. The results show that a NE-trending brightness temperature increase strip with a length of about 900 km and an amplitude of 12 K appeared three months before the Maduo earthquake, which has high similarity in spatial distribution and evolution characteristics with the anomaly characteristics of the MS7.1 Yushu earthquake on April 14, 2010. Furthermore, the appearing time and magnitude of the anomalies are related to the magnitude of the earthquakes. The anomalies of MS7.4 Maduo earthquake appeared earlier than MS7.1 Yushu earthquake with larger scale, and the temperatureincrease of microwave brightness due to both earthquakes reached more than 8 K. Preliminary mechanism analysis suggests that the pre-earthquake microwave anomaly stripes are consistent with the spatial distribution of NEward tensional fractures and extensional fracture zones in the region, and the appearance of the anomalies may be related to the geothermal activity of the fracture zones and the emissivity changes of surface rocks before the earthquakes.
Differences of geomagnetic anomalous field over Chinese mainland and its adjacent areas during 1960−2000 based on Taylor polynomial model
Yang Yujing, Feng Yan
 doi: 10.11939/jass.20220042
[Abstract](1) [FullText HTML](0) [PDF 20198KB](0)
This study adopts the geomagnetic measurements of the Chinese mainland in 1960.0, 1970.0, 1980.0, 1990.0, 2000.0, and the Taylor polynomial model to build up a medium-scale crustal magnetic anomaly model with low spatial resolution, associated with the fourth-generation geomagnetic comprehensive model (CM4). The figures of the anomaly field are drawn. The whole trends of the field are studied by putting all measurements into 2000.0. The differences in anomalies among different epochs have also been analyzed by the newest three-dimensional surface spline (3DSS) model derived from all available ground and aeromagnetic data. Results show that the intensity of the northward component X decreases with time, and its distribution shrinks to the southwest; the positive area of eastward component Y gradually moves to the west, and the negative area gradually occupies most of Chinese mainland; the distribution of vertical component Z is stable and is mainly negative in the study area, which implies that other factors do not likely influence the radial component. For the overall distribution of magnetic anomalies, components X, Z, total intensity F and horizontal component H are almost negative, which differs from CM4. Regarding the data consistency, the distribution of F has some similar features to the 3DSS model, which can illustrate more middle and small wavelength structures of the anomaly field. Large differences among the three models mainly come from the different measurement numbers, locations, and modeling theories.
P-arrival picking method of mining earthquakes combined with GRU and self-attention mechanism
Jiao Mingruo, Dong Fangjie, Luo Hao, Yu Jingkang, Ma Li
 doi: 10.11939/jass.20220034
[Abstract](28) [FullText HTML](8) [PDF 2568KB](12)
Seismic phase picking is the first key step of mine micro-seismic detection, and the accuracy of its results often directly affects the quality of subsequent event handling. Therefore, this paper proposed a method for P-arrival picking of mine micro-seism which based on deep learning method. The method firstly constructed the CNNDet model for events detection and P-arrival pre-picking; and then constructed the CGANet model to accurately pick up the P-arrival time for the detected events by introducing the self-attention mechanism and fusing the gated recurrent unit. Compared with STA/LTA, DPick and PpkNet, the incident detection’s accuracy and the recall ratio of our method are more than 98% for the test sets. The mean err and the standard deviation of P-arrival time are 0.014 s and 0.051 s, respectively. Our method is superior to the above three methods in terms of precision, the recall ratio and the standard deviation. In addition, the experimental tests on samples with different SNR prove that our method can still maintain high precision under low SNR. In the actual source location, our method also shows more excellent performance. In this paper, we proposed the P-arrival picking method based on gated recurrent unit and self-attention mechanism, which provides a new idea for micro-seismic monitoring and accurate identification of rock burst and other disasters.
Time-varying background field and anomaly analysis of Swarm satellite magnetic field data before the 2020 Jamaica MW7.7 earthquake
Zhu Kaiguang, He Xiaodan, Fan Mengxuan, Marchetti Marchetti, Wang Ting, Wen Jiami, Zhang Yiqun
 doi: 10.11939/jass.20210172
[Abstract](32) [FullText HTML](14) [PDF 3301KB](4)
The magnetic field data of Swarm satellite are influenced by geomagnetic activity and local time. In this paper, the influence of geomagnetic activity was firstly removed by variational mode decomposition, and then we built a time-varying background field to eliminate the influence of local time on the data. Based on the established time-varying background field, we used the Swarm satellite magnetic field data to conduct a pre-earthquake anomaly analysis of the 2020 Jamaica earthquake. We calculated the amount of energy of the magnetic data inside the earthquake affected area, then compared with the threshold value of the time-varying background field. If the difference between the amount of energy of a track inside the earthquake affected area and the corresponding background value is over the threshold value, the track was considered to be pre-earthquake anomalies. The results show that the cumulative number of anomalous tracks in function of the time shows accelerated growth from 50 days to 43 days before the earthquake. In addition, we also built day-side and night-side background fields to compare with the time-varying background field. By analyzing the differences between the anomalous orbits extracted based on the two methods, we find that the high-value background fields will be pulled down by the low-value background fields, which leads to some non-anomalous orbits being wrongly identified as anomalous orbits. For the same reason, the low-value background fields will be pulled up by the high-value background fields, which leads to some abnormal orbits cannot be recognized. It is because that the day-side and night-side background fields were built by the data of multiple local times magnetic field data, which cannot identify the great variations of magnetic field at different local time. However, the time-varying background field’s time resolution is high, and it can highlight the great variations of magnetic field at different local time. As a result, the establishment of time-varying background field is crucial for the accurate detection of anomalous orbits. Further, we analyzed the cumulative number of anomalies in lithosphere, atmosphere and ionosphere, and explained the time correlation of these anomalies, which proved that these anomalies may be related to the birth of the Jamaica earthquake.
Constrain low-velocity layer using higher-mode Rayleigh waves
Feng Xuanzheng, Lu Laiyu, Wang Shaotong, Qin Tongwei
 doi: 10.11939/jass.20210189
[Abstract](38) [FullText HTML](12) [PDF 5148KB](27)
Due to high sensitivity to S-wave velocity, Rayleigh-wave dispersion curves of the fundamental and higher modes are usually used to invert near-surface S-wave velocities in engineering geophysical exploration. For the model containing a low-velocity layer, the dispersion curves of the fundamental and higher modes show two typical characteristics. One typical characteristic is that the crossover would be observed between different modes, and the fundamental mode shows obvious indication of low-velocity characteristics in interested frequency range. For the other kind of model with low-velocity layers, the dispersion curves have no visual crossing phenomenon in the frequency range of interest, and the low-velocity characteristics may not be observed in the measured dispersion curves. For the latter model containing a low-velocity layer, which is often encountered in practice, investigations on the inversion of multimode Rayleigh waves are conducted in this paper based on seismic reflection data. Studies show that if the observed fundamental-mode dispersion curve does not include the frequency band sensitive to the depth of the low-velocity layer, the inversion based on the fundamental-mode alone may not be able to recover the low-velocity characteristics of the model. But the low-velocity layer can be reconstructed accurately by inversion considering both the fundamental and higher mode Rayleigh waves even the observed fundamental mode dispersion curve has no obvious indication of low-velocity characteristics.
A seismic data denoising method based on complete ensemble empirical mode decomposition with adaptive noise and Hurst exponent
Mao Shirong, Shi Shuiping, Yu Zhuangji, Su Meiyan, Li Sha, He Jiaxing, Fu Heng, Zhang Qing
 doi: 10.11939/jass.20210165
[Abstract](90) [FullText HTML](42) [PDF 4753KB](7)
In seismic observation, seismic data generally contain background noise, which reduces the efficiency of seismic analysis. Traditional denoising methods usually need a priori knowledge of noise, and some effective data will be lost when filtering. To solve this problem, this paper proposes a seismic data denoising method based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and Hurst exponent. Firstly, the magnetic detection signal is decomposed into a series intrinsic mode functions (IMF) by CEEMDAN method. Secondly, the Hurst exponent is used to identify the filtered IMF component. Finally, the IMF component of seismic data is reconstructed to realize data denoising. Compared with the denoising effect of traditional methods, the filtering ability of this method for low SNR waveform is improved by 32%, and the filtering ability for high SNR waveform is 6 times higher. At the same time, on the surface of geomagnetic data denoising results, this method can completely filter subway noise from geomagnetic signal waveform.
The characteristics of subway stray current on geo-electrical resistivity observation
Wang Lanwei, Zhang Yu, Zhang Xingguo, Hu Zhe
 doi: 10.11939/jass.20210197
[Abstract](1171) [FullText HTML](106) [PDF 17102KB](46)
The geoelectrical resistivity observation is one of the most important methods in the study of earthquake precursor, and the characteristics of the stray current during subway operation in the geoelectrical resistivity observation are useful for analyzing the geoelectric observation data and the anomaly variation before earthquake. Based on the study on the generation mechanism, the quantitatively results of the influence of stray current on geoelectrical resistivity observation were given in this paper. The result shows that the effect distance can reach dozens or even to a hundred kilometers. Through monitoring the stray current in some geoelectrical resistivity observation stations around cities, such as Beijing Tongzhou station, Tianjin Qingguang, Baodi and Tanggu stations, Jiangsu Jiangning station and Liaoning Xinchengzi station, the amplitude and frequency range of the stray current signal as well as its spatial distribution characteristics were analyzed. It shows that the amplitude of the signal ranges from several to tens millivolt, and the period range is mainly from 50 s to 200 s. Due to the influence of stray current, the signal-to-noise ratio is decreased by 10 to 30 dB, and the accuracy of the observation data is more than 20 times worse than the specified requirement. According to the characteristics of the stray current propagation, several methods which can be used to suppress the signal were proposed in this paper, and it will provide a foundation for the identification of anomaly information from the observation data and anti-interference technology study.
Applicability of the Next Generation Attenuation-West2 ground-motion models to the components of near-fault velocity pulse-like ground motions
Zhao Xiaofen, Wen Zengping, Xie Junju, Xie Quancai
 doi: 10.11939/jass.20210176
[Abstract](571) [FullText HTML](129) [PDF 9634KB](105)
The traditional ground-motion models (GMMs) do not account for pulse effects and may therefore fail to estimate seismic hazards and risk at near-fault sites, where pulse-like ground motions are expected. Thus, the applicability of the newest generation NGA-West2 GMMs to the near-fault velocity pulse-like ground motions need to be tested. The near-fault strong ground motions are quantitatively identified from recent earthquake since 2013 by considering the uncertainty of pulse orientation and using wavelet method so as to form a new pulse database. Based on the new pulse database, long-period pulses are extracted from the original pulse records by using wavelet method. Based on a quantitative analysis of the epsilon parameter, we quantitatively test the applicability of the NGA-West2 ground-motion model to the near-fault velocity pulse-like ground motions. The results show that the four NGA-West2 models are more suitable for describing the residual recordings at the studied period, but underestimate the pulse original ground motions especially around the pulse period. We noted that, during the four NGA-West2 models, the applicability of the CB2018 to the residual ground motions is the best. This study provides an excellent opportunity to quantitatively evaluate the NGA-West2 GMMs and to update these models in the near future, and also provides a basis for incorporating pulse effects into near-fault probabilistic seismic hazard analysis and seismic design.
Broadband ground motion simulations applied to the Luding MS6.8 earthquake on September 5,2022 based on spectral element method
Zhao Jingxuan, Ba Zhenning, Kuo Chenyang, Liu Bojia
 doi: 10.11939/jass.20220190
[Abstract](42) [FullText HTML](10) [PDF 12379KB](12)
At 12:52 on September 5, 2022, a MS6.8 earthquake occurred in Luding County, Garze Prefecture, Sichuan Province. The earthquake caused severe damage and heavy casualties in Luding County and its surrounding areas. In order to reproduce the ground motion influence field of the earthquake and analyze the spatial distribution characteristics of near-field ground motion, the deterministic asperity source model is combined with the random source model to obtain the kinematic hybrid source model. Then, the hybrid source model is developed into the SPECFEM 3D, and the whole-process broadband (0.1−5 Hz) ground motion simulation based on the spectral element method and kinematic hybrid source model is realized. Firstly, the simulation results are compared with the time history records of six stations, the corresponding response spectra and the NGA-West2 ground motion attenuation curves to test the applicability of the method. Secondly, the three-component velocity wave field snapshots of the earthquake is given to reproduce the directional effect and local site effect of the near field when the seismic wave propagates. Finally, the peak acceleration (PGA) and peak velocity (PGV) maps of the ground motion in the range of 100 km centered on the Luding area are given, and the spatial distribution characteristics of the ground motion in the near field intensity under the Luding earthquake are analyzed. Based on the simulation results, the seismic intensity distribution map is given. The results show that the epicenter PGA and PGV is close to 600 cm/s2 and 50 cm/s, respectively, and the seismic intensity reaches Ⅸ degree. Due to the influence of mountain-canyon topography in Luding area on the ground motion, the peak of ground motion is significantly amplified at the top of the mountain and the bottom of the canyon, and the amplification of PGA and PGV at the top of the mountain is 1.9 times and 1.5 times, respectively. The amplification of PGA and PGV at the bottom of the canyon is 1.7 times and 1.4 times. Attention should be paid to the phenomenon of earthquake amplification and possible secondary geological disasters in mountain-canyon region.
Spatial autocorrelation method based on dense short-period seismic array and its application in the Guangdong-Hong Kong-Macao Greater Bay
Pan Qi’an, Shen Xuzhang
 doi: 10.11939/jass.20220003
[Abstract](153) [FullText HTML](30) [PDF 2317KB](11)
Based on the spatial autocorrelation (SPAC) method, the dispersion curves of Rayleigh wave have been extracted from the ambient noise recorded by the dense short-period seismic array, and then the inversion of S-wave velocity structure beneath the observation nodes were carried out. We used the SPAC method to process the records of 21 stations belong to the dense short-period seismic array in the Guangdong-Hong Kong-Macao Greater Bay area. The dispersion curves have been obtained by combining the station-pairs with different distances, and then the inversion for shallow S-wave velocity structures within a depth of 1 km beneath the Panyu district, Guangzhou city, have been performed. The results show that the velocity beneath the array is obviously low above 0.25 km, ranging from 1.17 km/s to 1.59 km/s, while the velocity increases steadily to 2.88 km/s between 0.25 km to 1 km. This indicates that the stability and the reliability of the method, which also implies that the SPAC is an effective, economical and environmentally method for detecting the shallow fine structures in densely populated urban areas, and it will play an increasingly important role in the detection of shallow structure in urban areas in the future.
Discussion on the magnitude overestimation of the 1920 Haiyuan earthquake
Liu Jing, Xu Jing, Ou Qi, Han Longfei, Wang Zijun, Shao Zhigang, Zhang Peizhen, Yao Wenqian, Wang Peng
 doi: 10.11939/jass.20220051
[Abstract](49) [FullText HTML](33) [PDF 3683KB](20)
The great 1920 Haiyuan earthquake, resulting in tremendous casualties, ranks as one of the largest and most devastating earthquakes in China. This significant event marks the start of investigating earthquakes through modern scientific approaches in China. Recent studies show that the moment magnitude of the 1920 Haiyuan earthquake is MW7.9±0.2, prominently smaller than the widely known and often cited magnitude M81/2. This paper reviews the re-calibration and conversion of different magnitude types in the early developing phase of seismometers and analogue seismographs. Similar to the 1920 Haiyuan earthquake, the magnitude of many large shallow earthquakes that occurred in this period are systematically over-estimated due to factors such as developing technology, sparse instrumentation and data, and diverse calibration functions. The moment magnitude, linked to physical parameters of earthquake rupture, is the best magnitude scale. For magnitude is the most commonly used parameter in describing an earthquake’s size and energy and is an essential factor in seismic hazard assessment, bias and errors in magnitude conversion have significant consequences in understanding the spatio-temporal pattern of historical seismicity and the reliability of various products of seismic potential and hazard evaluation. We thus advocate citing revised moment magnitude MW7.9 for the 1920 Haiyuan earthquake in future studies and re-evaluating the magnitude of historical earthquakes in general. With a revised magnitude, the 1920 Haiyuan earthquake is similar in size to the 2008 Wenchuan earthquake (MW7.9, MS8.0) and the 2001 Kunlun earthquake (MW7.8, MS8.1).
Spatio-temporal relationship between source parameters such as stress drop and significant earthquakes in Changning-Xingwen area
He Xinjun, Zhang Xiaodong, Meng Lingyuan, Wang Yue
 doi: 10.11939/jass.20210196
[Abstract](29) [FullText HTML](10) [PDF 3009KB](6)
A MS6.0 earthquake with a focal depth of 16 km occurred with the epicenter of (28.34°N, 104.90°E) in Changning county, Yibin city, Sichuan Province on June 17, 2019. There were three strong aftershocks above MS5.0 within five days after the Changning earthquake and another MS5.6 earthquake occurred in Gongxian County on July 4. This paper relocated 1 948 ML≥2.0 earthquakes in Changning-Xingwen area during 2019 to 2020 by the double difference method based on the seismic phase observation report provided by the China Seismic Network. The distribution of 1 823 earthquakes above ML2.0 after relocation shows that the aftershock sequence in the northern area of Changning spreads along the NW-SE direction anticline. Moreover, the earthquakes in southern area is more scattered. We calculated source parameters such as seismic moment and stress drop based on 208 earthquakes with magnitude above ML3.0 in Changning, Sichuan from January 2019 to December 2020, and analyzed the evolution characteristics of seismic stress drop in the region before and after the Changning MS6.0 earthquake on June 17, 2019. The results show that the stress drop of ML3.0−3.9 earthquakes before the strong aftershocks significantly increased in Changning-Xingwen area, and most of the earthquakes with magnitude above ML4.0 occurred in the high stress drop area of ML3.0−3.9 earthquakes in the study area.
Determination of focal mechanism and seismic energy of Luding MS6.8 earthquake on September 5,2022
Li Zan, Liu Ruifeng, Wang Zibo, Hu Yansong, Kong Handong
 doi: 10.11939/jass.20220212
[Abstract](58) [FullText HTML](25) [PDF 2966KB](19)
Removing tilt noise from the vertical component data of ocean bottom seismograph: A case study on the data from the Pankun test in the South China Sea
Wu Yuechu, Yang Ting
 doi: 10.11939/jass.20220163
[Abstract](123) [FullText HTML](48) [PDF 0KB](28)
Due to the harsh marine environment, the noise level in the data of the passive source ocean bottom seismograph (OBS) is usually much higher than that of the land station. The noise generated by the interactions between the seismometer and bottom currents strongly affects the data quality of OBS, especially the signal-to-noise ratio of horizontal component data. Based on the correlations between the noise data of the horizontal and the vertical components, we can remove the tilt noise from the vertical component by using the transfer function of the horizontal-to-vertical component. Using the data from the 2019−2020 Pankun OBS South China Sea test, This paper describes the theory and process of this method. It compares the seismograms before and after removing the tilt noise and highlights the improvement of the dispersions of Rayleigh surface waves. The results show that removing tilt noise can improve the signal-to-noise ratio of seismograms in the low-frequency range, resulting in surface waves more conducive to imaging the deep structure of the oceanic lithosphere. This study also shows that although the tilt angle (1.0°) of the seismometer of Pankun OBS is much smaller than the tolerance of the tilt angle of the instrument (2.5°), the bottom currents still generate a significant level of tilt noise on OBS data. Therefore, the leveling system of the instrument is a crucial component affecting the OBS data quality.
Ocean bottom seismograph orientation and crustal structure of the Woodlark Rift
Gao Jia, Yu Youqiang
 doi: 10.11939/jass.20220091
[Abstract](70) [FullText HTML](42) [PDF 8824KB](22)
The Woodlark Rift in southeastern Papua New Guinea is a young continental rift and develops within the collision zone between the Australian and SW Pacific Plates, which offers an ideal location to explore the crustal structure beneath the incipient rift under a convergent setting. However, the sea water layer makes it difficult to collect high-quality seismic data, and the common step is to deploy the ocean bottom seismographs (OBSs) in a free-fall way. Therefore, mis-orientation of horizontal components of the OBS usually leads to failure of applying the inversion techniques such as the receiver function to the three-component waveforms. In this study, we employed both P-wave and Rayleigh-wave polarization analyses to determine all available OBS orientations, and then used the recorded teleseismic waveforms to conduct a receiver function study on the crustal structure beneath the Woodlark rift. The number of the receiver function traces has greatly increased after the orientation corrections and the crustal structures can be better constrained based on the results from P-wave polarization analysis. Contrasting crustal structures were revealed beneath the Kiribishi Basin and the Goodenough Basin where the rift axis is located. The crust beneath the Goodenough Basin is deciphered to thin towards the rift axis with an average of (33.3±2.42) km, while a much thinner crust is observed beneath the Kiribisi Basin with a mean value of (24.1±5.44) km. High vP/vS ratios were determined at all stations, which may be attributed to the Papuan ultramafic body and dehydration melting of subducted slab segments.
Seismic monitoring of typhoons: Recent progress and future prospects
Zhu Xinhui, Fang Sunke, Lin Jianmin
 doi: 10.11939/jass.20220191
[Abstract](56) [FullText HTML](27) [PDF 5843KB](17)
Typhoons are one of the most destructive meteorological disasters all over the world. However, because of the lack of in situ observations under such extreme weather conditions during the typhoon’s passage, typhoon monitoring and forecasting are still not able to meet the needs of typhoon prevention and mitigation. In recent years, a new method of typhoon monitoring based on seismological observations and techniques has emerged and developed, utilizing typhoon-generated seismic noise as a proxy. This paper reviews the recent progress in study of typhoon-induced microseisms, including the generation mechanisms, source location distribution, and its potential implications on typhoon monitoring and ocean wave parameter inversion. Future prospects on seismic monitoring of typhoons are provided and discussed. This newly emerging method may provide interdisciplinary support to traditional observation and investigation of typhoons.
Geodynamical simulation of the effects of ridge subduction on the scale of the seismogenic zone south of Chile Triple Junction
Guo Changsheng, Sun Pengchao, Wei Dongping
 doi: 10.11939/jass.20210192
[Abstract](129) [FullText HTML](61) [PDF 6409KB](29)
Earthquakes are much more frequent to the north of Chile Triple Junction than to the south, where the thermal anomaly is also more significant. To study the effects of ridge subduction on the thermally defined seismogenic zone, two-dimensional finite element models were established based on the geology of Chile Triple Junction, the process of ridge subduction was simulated, and the effects of the initial slab dip and the convergence rate on the seismogenic zone were compared. The results show that the width of the seismogenic zone decreases during the ridge subduction, inducing earthquakes to occur much less to the south than to the north of Chile Triple Junction. By comparing the observed data in the vicinity of the profiles with the numerical simulation results, we find that the numerical simulation can roughly reflect the width of the interplate seismogenic zone and the surface heat flow in the area of Chile Triple Junction. At the same convergence distance, a larger convergence rate comes with a wider seismogenic zone and the deeper the downdip limit of the seismogenic zone, the higher the surface heat flow in the vicinity of the trench. Compared with the convergence rate, factors such as slab dip have little effect on the surface heat flow. In the process of ridge subduction, larger the slab dips leads to narrower seismogenic zones. When the effect of shear heating is included in the simulation, the width of the seismogenic zone in the process of ridge subduction can shrink to about 15 km and the depth of the seismogenic zone is small. Such a narrow and shallow seismogenic zone makes it hard for earthquakes to occur and for the Wadati-Benioff plane to be observed in some areas south of Chile Triple Junction.
Short Duration Events on OBS recordings in the Northwestern Sub-basin of the South China Sea
Wang Yizhi, Yang Ting, Liu chenuang, Liu Dan, Wu Yuechu
 doi: 10.11939/jass.20220175
[Abstract](112) [FullText HTML](35) [PDF 5544KB](40)
Based on the analysis of the data on broadband OBSs deployed in the northwestern sub-basin of the South China Sea (SCS) from October 2019 to May 2020, we detected more than 120 000 Short Duration Events (SDEs) at one station by using STA/LTA algorithm. These SDEs are classified as consecutive short duration events (C-SDEs) and random short duration events (R-SDEs) according to their characteristics and generation mechanism. C-SDEs occur over several hours or days consecutively and regularly. The interval between the two Group Events (GEs) is about 100-300s and contains 3−10 single-wave (SW) with a duration of about 1s. The dominant frequencies of C-SDEs range from 20 Hz to 44 Hz, likely depending on the distance from the sources. C-SDE has strong energy and record on three OBS stations spaced about 105 km apart. The R-SDEs have the dominant frequency ranging from 8 Hz to 25 Hz with double frequency peaks on the spectrum and a duration of 0.3−2 s. Due to the limited energy of the R-SDEs, it is not easy to detect the same event on multiple stations. We present the possible generation mechanisms for C-SDEs and R-SDEs, respectively. We infer there are active C-SDE sources in the northwestern sub-basin of the SCS. They may result from human activities, such as air gun firing or low-frequency hydroacoustic communication signals. The R-SDE sources appear close to the OBS stations, likely generated by the ruptures due to gas escape from seafloor sediments. R-SDEs on OBS recordings indicate persistent gas leakages from the sedimentary layer in the northwestern sub-basin of the SCS.
Probability hazard analysis of potential earthquake-induced landslide:A case study of Longxian County, Shanxi Province
Fu Guochao, Pan Hua, Cheng Jiang, Zheng Lifu
 doi: 10.11939/jass.20210147
[Abstract](133) [FullText HTML](53) [PDF 6767KB](30)
Abstract : In this paper, the potential focal area division scheme of the new generation seismic zonation map of China combined with the Newmark displacement model is adopted. According to the engineering geological lithology and topographic elevation data of Longxian the amplification effect of ground motion topographic and the uncertainty of parameters of Newmark model are also considered. The instability probability of landslide in Longxian county, Shanxi province is given when the earthquake incidence rate is 10% in 50 years. According to the results, potential earthquake-induced landslide in the study area can be divided into four grades: the very low risk area, the low risk areas, the medium risk areas and the high risk areas. And the high risk areas are mainly concentrated in the mudstone, siltstone and loess covered areas with a slope of more than 40° in Longxian. Among them, Qianhe River and some areas on both sides of Tongguan River have higher seismic landslide risk. The results can provide a reference for seismic landslide risk management and land planning in this area.
Development characteristics and controlling factors of co-seismic geo-hazards triggered by the Luding MS6.8 earthquake occurred on September 5, 2022
Zhang Jiajia, Chen Long, Li Yuanling, Liu Minsheng, Shi Shengwei, Yi Jingsong, Zhang Wen, Zhang Shilin, Sun Jinhui, Yang Dong, Xian Jieliang, Cai Jiajun
 doi: 10.11939/jass.20220215
[Abstract](221) [FullText HTML](31) [PDF 8404KB](72)
Based on the field investigation of the Luding earthquake (MS6.8) occurred on September 5, 2022, combined with the remote sensing interpretation, the development characteristics and controlling factors of co-seismic geo-hazards triggered by the Luding earthquake are summarized, and the evolution trend of co-seismic geo-hazards is studied and judged. According to the different phases of prevention and mitigation of co-seismic geo-hazards, corresponding suggestions are given in order to benefit the prevention and control of geo-hazards. The results show that the co-seismic geo-hazards of the Luding earthquake are mainly small-medium-sized collapses and landslides, which are concentrated in three areas: Moxi town and Hailuo gully, Wandong village of Detuo town and both banks of Dadu River in Detuo town. Mainshock and aftershocks, Xianshuihe active fault, topography, special rock and sediment mass are the main controlling factors of spatial distribution of co-seismic landslides triggered by the Luding earthquake. The geo-hazards after Luding earthquake will be extremely active in the next 10 years. It is necessary to pay close attention on the high-locality and steep slopes on both banks of the Moxi River and its tributaries, the Dadu River, the high-locality terrace along the Dadu River, the edge area around the Moxi platform, and the debris flows in Moxi town and Detuo town where co-seismic landslides are densely developed ; According to the management logic of emergency prevention of co-seismic geo-hazards, it is suggested that local governments should follow the three phases of detailed investigation, restoration and reconstruction, and long-term planning.
Rupture process of the MS6.9 Menyuan,Qinghai, earthquake on January 8, 2022
Dai Danqing, Yang Zhigao, Sun li
 doi: 10.11939/jass.20220032
[Abstract](248) [FullText HTML](94) [PDF 3242KB](67)
Based on the waveform data observed by the near field strong-motion stations, the earthquake rupture process can be quickly and stably inverted. This paper collected waveform data recorded by the strong-motion stations reconstructed in Qinghai during the implementation of the National Rapid Intensity Report and Seismic Early Warning Project. Based on these data, the rupture process of the Qinghai MS6.9 earthquake on January 8, 2022 was inverted by the iterative deconvolution and stacking method (IDS). The rupture model from inversion show that the rupture extends from the initial rupture point to a unilateral rupture in the southeast-east direction, with a duration of about 14 seconds (mainly focus on 2−8 seconds), a maximum slip of 3.6m, and a rupture length of about 20 km. The rupture extends longitudinally from the deep to the shallow, which is consistent with the surface rupture found in the field investigation. The spatial distribution of aftershock sequences shows significant segmentation characteristics, indicating complex tectonic transitions in the rupture zone. There is still the possibility of strong earthquakes in this area in the future.
Rupture process of the January 2022 Menyuan,Qinghai MS6.9 earthquake revealed by inversion of regional broadband seismograms
Zhu Yinjie, Luo Yan, Zhao Li
 doi: 10.11939/jass.20220148
[Abstract](251) [FullText HTML](94) [PDF 4789KB](75)
Based on regional broadband waveform records, we investigate the rupture process of the January 2022 Menyuan MS6.9 earthquake by using the finite fault inversion method, and then combined with the geological knowledge and aftershock relocation results to determine the actual rupture fault., The inversion results show that the Menyuan earthquake occurred on a WNW-trending strike-slip fault. The rupture mainly occurred on both sides of the hypocenter, with a bilateral rupture characteristic. The maximum ruptures on the two sides of the hypocenter occurred at 2 s and 9 s. In terms of rupture scale, the depth of obvious rupture and the length of surface rupture are about 16 km and 20 km, and the maximum slip of 1.5 m occurs at about 6km. The seismic energy is mainly released in the first 15 s. The total seismic moment released is 1.23×1019 N·m, equivalent to MW6.67. The dip angle of the seismogenic fault plane is 84.6°, almost vertical. Due to the large range of rupture, the surface projection of obvious rupture is up to 34 km.
An estimation model of high frequency attenuation coefficient of ground motion for local site
Lang Ziping, Yu Ruifang, Xiao Liang, Fu Lei, Zhou Jian
 doi: 10.11939/jass.20220053
[Abstract](181) [FullText HTML](76) [PDF 2205KB](43)
When using the stochastic finite fault method for ground motion simulation, how to select reasonable parameters to describe the near-surface high-frequency attenuation characteristics of a specific local site has important practical significance for evaluating the correctness of ground motion simulation results. In the prediction of ground motion parameters of engineering sites, how to quickly determine the value of this parameter is an urgent problem to be solved in practical applications. Firstly, the correlation that between the high-frequency attenuation coefficient κ0 of the site and the average shear wave velocity vS30 was analyzed; Then, based on the 546 κ0 coefficients calculated by domestic and foreign scholars, the root mean square value of κ0 in a certain time window was used to discuss its variation trend with the increase of the average shear wave velocity vS30.The results showed that although κ0 had obvious regional differences, its root mean square value showed a decreasing trend with the increase of vS30In order to obtain a reasonable κ0 estimation model, the linear function, polynomial function, logarithmic linear function and log-log linear function were used to preliminarily fit the relationship between the root mean square value of κ0 and vS30. The results show that the logarithmic linear function can be better describe the relationship between κ0 and vS30. Finally, based on the 477 data obtained from the screening, the model parameters were fitted by the least square method, and a practical model of κ0- vS30 suitable for engineering applications was obtained. The analysis of the applicability of the model shows that the κ0 estimation model constructed in this study can reasonably estimate the high-frequency attenuation of ground motion when predicting site ground motion parameters.
Shallow velocity structure and seismogenic environment in the Zigui section of the Three Gorges Reservoir region of China
Hu Jintao, Xie Jun, Wei Zigen, Jin Chao
 doi: 10.11939/jass.20210194
[Abstract](321) [FullText HTML](72) [PDF 3065KB](71)
After the impoundment of the Three Gorges Reservoir in 2003, shallow earthquakes occurred frequently, which had a great impact on local productions and lives. The study of shallow velocity structure is of great significance for shallow seismic disaster assessment and disaster prevention and reduction in Zigui area. In this paper, based on the vertical component continuous waveform records of 24 mobile seismic stations in Zigui area from June to July of 2020, the empirical Green’s functions between stations are obtained by cross-correlating of the ambient seismic noise, the Rayleigh wave group velocity dispersion curves of 0.6−5 s are extracted, and the inversion for the three-dimensional S-wave velocity model is obtained within 6 km near the surface of the region. The results show that the S-wave velocity of Zigui basin and its south adjacent area is significantly lower than that of the eastern fault area, which is consistent with the structural evolution and sedimentary characteristics of different structural blocks in the studied area; an earthquake with MS4.2 occurred on the vertical high-velocity and low-velocity junction area of the study area in 2014. The S-wave velocity decreases obviously near the Yangtze River region in the fault zone, indicating that the Yangtze River water penetrates into the fault area. Therefore, the frequent occurrence of earthquakes in Zigui area is related to the water load and water infiltration of the Three Gorges reservoir.
Display Method:
2023, 45(1).  
[Abstract](52) [PDF 1109KB](24)
Joint inversion of multi-station receiver functions and gravity data for imaging Moho variations and average crustal vP/vS ratios
Hao Aowei, Zhang Haijiang, Han Shoucheng, Gao Lei
2023, 45(1): 1-16.   doi: 10.11939/jass.20210179
[Abstract](490) [FullText HTML](208) [PDF 2792KB](183)
Crustal thickness and vP/vS ratio are two important parameters for understanding crustal structure and composition, which can help to study regional tectonics. Receiver function analysis has been widely used for determining crustal thickness and vP/vS ratio by the H-κ method or the H-κ-c method. However, it can only acquire average crustal thickness and vP/vS ratio beneath each seismic station, but cannot constrain their lateral variations among seisimic stations due to their sparse and irregular distribution. On the other hand, the gravity data has been widely used to derive the Moho variaitons, which has a good coverage and resolution laterally but poor resolution vertically. Therefore, in this study we have developed a new joint inversion method of receiver functions and gravity data to simultaneously invert for variations of Moho depths and average crustal vP/vS ratios in a region. The method takes advantage of complementary strengths of receiver functions and gravity data, and can simultaneously fit all receiver functions and gravity data in the region. The synthetic tests show that the proposed joint inversion method produces more reliable results than only receiver function analysis, especially for the crustal thickness.
Impact of dynamic stress on aftershock triggering of the 2021 Yunnan Yangbi MS6.4 earthquake
Liu Rong, Chen Qiang, Yang Yinghui, Zhong Xia, Yuan Yu
2023, 45(1): 17-28.   doi: 10.11939/jass.20210157
[Abstract](177) [FullText HTML](96) [PDF 6520KB](100)
Based on the waveform data of IRIS teleseismic station, this paper inversed the focal rupture process of Yunnan Yangbi MS6.4 earthquake, calculated the dynamic Coulomb rupture stress change caused by fault rupture in near field and discussed the dynamic stress triggering effect of main shock on near-field aftershock activity. The results show that the evolution process of dynamic Coulomb stress is consistent with the inversion results of source fracture characteristics, and its size distribution is also well correlated with the density of seismic sequence distribution. The static and dynamic Coulomb rupture stress produced by the main shock promote the occurrence of aftershocks, but compared with the static stress, the proportion of aftershocks located in the positive Coulomb rupture stress area is increased by 21%, and the positive and negative areas of aftershocks and dynamic Coulomb stress change have better consistency. The dynamic stress can better explain the spatial characteristics of aftershocks distribution after the earthquake. Small earthquakes cluster at 10 km perpendicular to the main trunk of the earthquake sequence, which may be caused by the dominant dynamic Coulomb fracture stress produced by the main earthquake. Quantitative analysis of the dynamic stress triggering of the main shock to the aftershock shows that within one week after the main shock, eight aftershocks receiving points bigger than MS4.0 are triggered by the dynamic Coulomb rupture stress.
Experiment and numerical simulation of co-seismic water level response in unconsolidated confined aquifer
Zhai Zeyu, Gu Hongbiao, Zhang Yan, Kong Huimin, Chi Baoming
2023, 45(1): 29-45.   doi: 10.11939/jass.20210149
[Abstract](188) [FullText HTML](95) [PDF 2646KB](88)
In order to promote understanding mechanisms of co-seismic response of water level in well shaking table experiments have been carried out with sinusoidal loading in different  vibration frequencies and amplitudes (accelerations) for complete well unconsolidated confined aquifer system. The physical model has been built based on experimental model, and fluid-solid coupled model of pore pressure response in unconsolidated aquifer and mathematical model of flow interaction between aquifer well under vibrations have been established. The experimental processes have been simulated in COMSOL Multiphysics, a multi-field coupling simulation software. Four typical water level variation forms observed in experiment are similar to those of field studies, and the results of numerical simulation show that the mathematical model established in this study can well reflect the response of pore water pressure and water level in unconfined aquifer. This research is of great significance to explain the mechanism of co-seismic responses of groundwater, and stability and safety of seepage in rock and soil mass.
Anomaly edge enhancement and topographic correction technology of linear source 3D borehole-to-surface electrical method
Xiong Zhitao, Tang Xingong, Zhang Lianqun, Li Dandan, Yu Junhu
2023, 45(1): 46-61.   doi: 10.11939/jass.20220074
[Abstract](166) [FullText HTML](123) [PDF 4175KB](61)
Based on the finite element method of unstructured grid, the efficient forward modeling of the borehole-to-surface electrical method derived by the linear current source under the condition of the 3D complex geoelectric model was carried out. The effects on the effectiveness and accuracy of the borehole-to-surface electrical method imaging were discussed by obtaining the electric field response derivative to characterize the boundary range of the target body, and using the difference field topography correction technology to eliminate the topographic influence. And the comparison between the numerical solution and the analytical solution verifies the effectiveness of the algorithm in this paper. The model calculation results show that the spatial position and direction of the roadway with water accumulation cause significant changes in the apparent resistivity, and the extreme value of the apparent resistivity change rate accurately and clearly indicates the boundary position of the roadway. The normalized total horizontal derivative of the electric potential greatly improves the ability of the borehole-to-surface electrical method to identify the complex boundary position of the target body. Moreover, the influence of topography on the distribution of borehole-to-surface electrical field is also serious, and its apparent resistivity response is approximately symmetrical to the shape of the topography. The difference field technique can effectively weaken the influence of topography on the high-precision imaging of the borehole-to-surface electrical method. The research results have important theoretical and practical significance for improving the data interpretation level and application effect of the borehole-to-surface electrical method.
Feature and mechanism of geoelectric field related to atmospheric pressure
Li Xuebo, Wei Dingjun, Li Xuetao, Luo Long
2023, 45(1): 62-75.   doi: 10.11939/jass.20210127
[Abstract](117) [FullText HTML](62) [PDF 4797KB](80)
Using the geoelectric field data recorded by four geoelectric stations in Ningxia, the variation characteristics, spectral characteristics, the relationship with regional pressure variation, and the relationship between the measuring direction and the strike of nearby faults are studied. The research results show that part of the geoelectric field has diurnal variation characteristics, and also has the characteristics of non-periodic variation of atmospheric pressure, which is negatively correlated with the variation of atmospheric pressure, and the correlation is related to the angle between the measuring direction and the strike of nearby faults. It is considered that the geoelectric field has the characteristics of non-periodic change of atmospheric pressure is caused by the fluid “channeling” resulting from the change of air pressure system in the seepage process, which is due to the permeability difference between the bedrock pores and the nearby fault fractures.
Characteristics of the dominant azimuth anomalies of geoelectric field at Dawu station before MS7.4 Maduo,Qinghai earthquake in 2021
Zhao Yuhong, Su Weigang, Feng Lili, Li Xia, Liu Lei, Sun Xihao
2023, 45(1): 76-83.   doi: 10.11939/jass.20210162
[Abstract](122) [FullText HTML](74) [PDF 1675KB](77)
In order to know whether there were seismic electrical signals before MS7.4 Maduo, Qinghai earthquake on 22 May 2021, this paper analyzed the original data of geoelectric field from Dawu seismic station by using the dominant azimuth method, and the variation characteristics of rockmass fracture structure before the MS7.4 Maduo earthquake were obtained. Furthermore, the rockmass frasture structure characteristics of eight geoelectric stations within 500 km of the earthquake and previous related earthquake cases are comprehensively analyzed. The results show that the geoelectric field dominant azimuths of the two observation sites at Dawu had a significantly synchronous deflection phenomenon eleven months before the earthquake, and the geoelectric field of one site increased sharply again one month before the earthquake. The abnormal characteristics of the site are mainly manifested as the rapid deflection of the jump range of the dominant azimuth, with the maximum deflection reaching 45°−90°. Additionally, the stations Garze and Maqu in the same secondary block showed quasisynchronous changes with the Dawu station, while the stations in other secondary blocks showed no anomalies, indicating that the abnormal responses are affected by regional tectonic settings. And combined with the previous earthquake case analyses, it is deduced that the dominant azimuth anomaly based on the Dawu electric field has good prediction efficiency for the short and medium term earthquake.
Geochemical characteristics of soil gas in the north margin fault of Huaizhuo basin,Hebei Province
Tang Jie, Zhang Suxin, Sheng Yanrui, Wang Jiang, Ding Zhihua
2023, 45(1): 84-97.   doi: 10.11939/jass.20210116
[Abstract](129) [FullText HTML](78) [PDF 2348KB](73)
Two surveying lines were carried out in Haojiapo and Xiaoshuiyu of Huaizhuo basin, Hebei Province, and four periods of Rn, CO2 and Hg concentrations were measured. This paper studies the spatial differences of soil gas geochemical characteristics in the southwest and northeast segments of the northern margin fault of the basin and its possible relationship with fault activity. The results show that the average concentrations of soil gas Rn, CO2 and soil Hg in Haojiapo profile are 8 371.16 Bq/m3, 0.85% and 14.82 ng/m3, respectively, and those in Xiaoshuiyu profile are 2 813.18 Bq/m3, 0.42% and 13.08 ng/m3 respectively, suggesting that the former are higher than the latter. The spatial difference of concentration distribution characteristics may be caused by different fault activity and fault fragmentation degree. The comparative analyses of regional soil Hg (total mercury, Hereinafter THg) concentration and soil gas measurement concentratio show that the two contents are consistent in spatial distribution, and the high-value abnormal points are distributed near the fault zone. Combined with the regional fixed-point precursory observation data and seismicity analyses, it is considered that the current activity of the fault is relatively weak. Therefore it is feasible to detect the shallow position of concealed faults in this area by using the distribution of soil gas concentration. At the same time, continuous observation of soil gas concentration has certain indicating significance for judging the fault activity in this area.
Estimating stress drop of the 2013 Lushan earthquake sequence based on the empirical Green’s function spectral ratio method
Fan Yehao, Wang Hongwei, Wen Ruizhi, Ren Yefei
2023, 45(1): 98-106.   doi: 10.11939/jass.20210155
[Abstract](240) [FullText HTML](71) [PDF 1722KB](81)
We adopted the 2013 Lushan aftershocks as a typical example, to investigate the feasibility of estimating corner frequency and stress drop by the empirical Green’s function (EGF) spectral ratio method based on the strong motion observation data. Firstly, we suggested the quality standard on the EGF spectral ratio curve to guarantee the reliable estimation of seismic corner frequency and stress drop. The corner frequencies for the 17 Lushan aftershocks with magnitude in the range of 3.8−5.4 were then estimated. Referring to the seismic moment magnitude given by other studies, we further computed the seismic stress drops.The results show that the corner frequency of Lushan strong aftershocks is mainly in the range of 1.0−2.0 Hz, the average stress drop is 9.98 MPa, and seismic stress drop presents obvious dependency on seismic magnitude.
A transfer function based on Laplace transform for correcting narrow-frequency velocity recording
Sun Yixuan, Xu Guolin
2023, 45(1): 107-115.   doi: 10.11939/jass.20210182
[Abstract](231) [FullText HTML](102) [PDF 3488KB](82)
Affected by the flat response range of the narrow-band seismograph, the narrow-band velocity recording has the problem of low-frequency component distortion, which limits the usable range of the seismic recording. To solve this problem, this paper deduces an improved transfer function based on the Laplace transform and bilinear transform to realize the correction from narrow-band seismic records to broadband ones. And then the Japanese Hi-net velocity records are used as an example for correction, and the corrected velocity records are compared with the KiK-net acceleration integral velocity records from the same station. The results show that the original velocity records are distorted at low frequencies, while the corrected waveforms are consistent with the KiK-net acceleration integral velocity records. The analyse show that the improved transfer function can effectively solve the distortion of the low-frequency components in the original velocity records, which effectively widens the usable range of low-frequency. Moreover, compared with the Nakata-corrected velocity recording method, the velocity recording corrected with the transfer function given in this paper is more accurate in terms of amplitude and waveform.
Experimental study on seismic wave attenuation compensation based on convolution principle and improved generalized S-transform
Jia Baoxin, Liu Guoyu, Zhou Linli
2023, 45(1): 116-125.   doi: 10.11939/jass.20210136
[Abstract](152) [FullText HTML](98) [PDF 2962KB](82)
In order to recover the attenuation loss caused by the vibration wave energy in the process of propagation, the inverse Q filtering method based on the convolution principle and the improved generalized S-transform is proposed. Through the vibration attenuation compensation model test, the time-frequency characteristics of the test data are analyzed by improving the generalized S-transform, and the energy distribution of the signal and the corresponding relationship between time and frequency are obtained. The method of quality factor based on convolution principle is used to obtain the time-varying Q value. The test data are processed using inverse Q filtering, and the vibration wave energy is compensated. The results show that the inverse Q filtering method proposed in this paper improves the compensation effect of seismic wave energy attenuation, broadens the frequency band of seismic data, improves the resolution of seismic data, and is conducive to the development of high-resolution seismic exploration, deep signal enhancement and oil and gas reservoir prediction.
Evaluation of early warning capability of Fujian Province seismic network
You Xiuzhen, Lin Binhua, Li Jun, Guo Yang, Yu Weiheng, Li Shuilong
2023, 45(1): 126-141.   doi: 10.11939/jass.20210173
[Abstract](231) [FullText HTML](135) [PDF 6016KB](103)
Since the common root-mean-square method and noise power spectrum method cannot eliminate the noise interference recorded by different types of sensors, we use the maximum probability peak displacement as the background noise evaluation index to calculate the noise level more accurate. Based on the reliable noise data, referring to the magnitude maximum distance monitoring capability method and considering the timeliness of earthquake early warning (EEW), an EEW minimum magnitude evaluation method is proposed. This new method can systematically evaluate the minimum magnitude of EEW and the warning time of independent three types of sensor networks and their fusion networks in Fujian. The results show that the minimum magnitude of EEW based on the fusion networks of the seismometer and the strong seismometer is higher than that of the single seismometer network, and obviously lower than that of the strong seismometer network. For fusion networks of strong seismometer and intensity meter, the minimum magnitude of EEW is similar to that of single intensity meter network. After integrating three types of networks, the minimum magnitude of EEW in 95% regions is about ML3.2. Because the density of intensity meter network is higher than the seismometer and strong seismometer network, the warning time is the shortest. Compared with the single seismometer network or single strong seismometer network, the warning time of EEW has been significantly reduced by three types sensor fusion networks, and the warning time in 95% regions is 4−6 seconds after an earthquake occurred as it is estimated. This study provides a reference to optimize the distribution of networks and increase the monitoring capacity of key regions in Fujian province.
Development and future directions of the disaster awareness research in China:An integrated identification coupling scientometric method and literature content analysis
Zhang Tengfei, Su Guiwu, Qi Wenhua, Wei Benyong, Pei Minchao
2023, 45(1): 142-166.   doi: 10.11939/jass.20210163
[Abstract](147) [FullText HTML](87) [PDF 3090KB](86)
Raising people’s disaster awareness is a prerequisite for motivating their behavior and strengthening their disaster-coping capacities. “Disaster awareness” has long been a very commonly used term in both academic community and ordinary people’s daily life. However, scientific discussion and exploration on it still remains far from sufficient so far. Using an integrated approach combined CiteSpace’s scientometric method and literature content analysis, this paper therefore aims to diagnose in particular the current status and future trends of the research of public awareness of disaster (PAD) in China that are evidenced by the relevant literature collected in CNKI from 1990—2019. The results reveal that: ① The PAD research has received an ever-increasing attention in China in the past three decades, involving a broad spectrum of disciplines and featured greatly by the multidisciplinary and/or interdisciplinary. However, the total publications and academic concerns on it are considerably less, and even much less than those on other disaster-focused topics (esp. those on disaster risk). ② Chinese existing PAD researches can be largely identified as the following five major aspects: PAD survey and measurement, PAD promotion pathways in formal education field, PAD encouragement strategies through science-popularization, PAD & bottom-up level of disaster reduction practices, and PAD & top-down direction of disaster reduction policies. Generally, large room for improvement exists on all these five aspects. In a view of specific hazard types addressed, earthquake and meteorological hazards have relatively been placed a concentrated position. ③ The overall trends or future directions are as follows: ① Specific research contents on PAD get more and more refined, associated exploration depths become deeper and deeper, and the situation of “all flowers bloom together” clearly develops; ② The connection between academic research and practical disaster reduction requirement grows tighter and tighter, especially so does the connection between research and bottom-up level requirement; ③ Disaster reduction-focused formal education and science-popularization, and meteorological disasters under changing climates are exactly the current hotspots. Based on these findings, we finally offered some suggestions, hoping to facilitate PAD research in China and beyond.